How to add orderby parameter for sorting on category.php

Question

I'm on a Category.php page which does the loop like this:

<?php while ($wp_query->have_posts()) : $wp_query->the_post(); ?>

I usually do a custom loop like this:

<?php //Define the Loop
    $temp = $wp_query;
    $wp_query= null;
    $wp_query = new WP_Query();
    $wp_query->query('posts_per_page=2&orderby='.$orderBy.'&paged='.$paged);
    ?>

I want to add the orderby variable to the first loop (the one on category.php) but can't figure out how to implement it.

Answer 1

You can use the pre_get_posts action hook to set the order on your category archive like so:

add_action('pre_get_posts', 'filter_category_orderby');

function filter_category_orderby( $query ){
    if( $query->is_category()){
        $query->set('orderby', 'title');
    }
}

just paste this snippet in your theme's functions.php and you should be fine.

Answer 2

If it's the main loop, you could use query_posts to add the orderby variable.

For example, you could order by title by putting this PHP code above the loop :

 global $query_string;

 query_posts( $query_string . 'orderby=title' );

 //Your while here